A motor vehicle body which is assembled from a plurality of individual frame pieces, each formed through an extrusion process is known, for example, from U.S. Pat. No. 4,618,163 (Hasler et al.). In Hasler, the extruded metal profiles are held together by specially devised node connector elements. This technique for motor vehicle body construction is adequately cost-favorable for small scale production. However, in the case of large scale production, it is preferable to form the frame pieces out of sheet metal rather than by a metal extrusion process, in view of the economies of scale involved.
A disadvantage with using sheet metal as a frame piece material is the difficultly in forming frame pieces with a desired cross sectional configuration which also appropriately balances the variables of weight and rigidity. Moreover, specially constructed metal forming machines are necessary for this task, thereby adding to the expense. Accordingly, sheet metal is primarily used in the finishing process to form the outer skin of the vehicle body.
Accordingly, there is a need in the art for the design of a motor vehicle body using frame pieces constructed of a combination of both extruded metal profiles and sheet metal in a manner that optimizes the strengths of each material so that various and intricate cross sections can be economically produced.